1. Department of Otorhinolaryngology, Head and Neck Surgery, University of Bonn, Bonn, Germany;
2. Department of Nephrology and Rheumatology, University Medical Center Göttingen, Göttingen, Germany;
3. Department of Otorhinolaryngology, Head and Neck Surgery, University of Munich, Munich, Germany;
4. Department of Otorhinolaryngology, Head and Neck Surgery, University Medical Center Göttingen, Göttingen, Germany;
5. Department of Internal Medicine, Cardiology and Pulmonology, University of Bonn, Bonn, Germany